5. TUMOR
VULNERABILITY OF THE BRAIN
Although the brain is the most protected organ, many
pathological processes can damage it or disrupt its functioning.
A lot of things about the functions of the human brain has
been learned by studying people with brain damage.
Major categories of the neuropathological conditions E.G
Tumors, seizure disorder, cerebrovascular accidents, disorders
of development, degenerative disorders, and disorders caused
by infectious diseases
behavioral effects of these conditions and their treatments
6. WHAT IS
A TUMOR ?
A tumor is a mass of cells whose growth is
uncontrolled and serves no useful function
1. BENIGN (Harmless)
Is a kind of tumor that has a distinct border between
the mass of the tumor cells and the surrounding tissue.
Does not re-grow.
2. MALIGNANT (Cancerous)
This kind of tumor grows by infiltrating the
surrounding tissue.
Reproduces
7. How do tumors damage the brain?
compression and infiltration
1. Compression:
A benign tumor occupies space and thus pushes against the
brain.
The compression can directly destroy brain tissue, or blocks
the flow of cerebrospinal fluid and causes hydrocephalus.
2. Infiltration
malignant tumors, cause both compression and infiltration.
As a malignant tumor grows, it invades the surrounding
region and destroys cells in its path.
8. Types of brain tumors
1. Gliomas:
Glioblastoma multiformae (poorly differentiated glial cells)
Astrocytoma (astrocytes)
Ependymoma (ependymal cells that line ventricles)
Medulloblastoma (cells in roof of fourth ventricle)
Oligodendrocytoma (oligodendrocytes)
2. Meningioma (cells of the meninges)
3. Pituitary adenoma (hormone-secreting cells of the
pituitary gland)
9. 4. Neurinoma (Schwann cells or cells of connective tissue
covering cranial nerves)
5. Metastatic carcinoma (depends on nature of primary
tumor)
6. Angioma (cells of blood vessels)
7. Pinealoma (cells of pineal gland)
10. SEIZURE
DISORDERS
A seizure is a sudden surge of
electrical activity in the brain.
seizure disorder instead of Epilepsy
The electrical activity is caused by complex chemical
changes that occur in nerve cells.
Brain cells either excite or inhibit other brain cells from
sending messages. Seizures are not disease but symptoms.
11. Seizure disorders cont…
In ancient religious traditions, seizures were
considered to be God’s punishment or the work of
demons.
However, as early as the fifth century B.C.E.,
Hippocrates noted that head injuries to soldiers and
gladiators sometimes led to seizures like the ones he
saw in his patients, which suggested that seizures
had a physical cause (Hoppe, 2006).
12. Classification of seizure disorders
•1. Tonic-clonic (Grand mal)
•2. Absence (Petit mal)
•3. Atonic (loss of muscle tone: temporary paralysis
1.Generalized
seizures(with no
apparent local onset)
•1. Simple Partial seizure (no major change in conscious)
•a. Localized motor seizure
•b. Motor seizure, with progression of movements as seizure spreads along the
primary motor cortex
•c. Sensory (somatosensory, visual, auditory, olfactory, vestibular)
•d. Psychic (forced thinking, fear, anger, etc.)
•e. Autonomic (e. g., sweating, salivating, etc.)
•2. Complex Partial seizure (Altered consciousness)
2.Partial seizures
(starting from a
focus)
13. EFFECTS OF SEIZURES
ON DIFFERENT BRAIN LOBES
Occipital
• Visual symptoms such as spots of color, flashes of light, or temporary blindness.
parietal
• Can evoke somatosensations, such as feelings of pins and needles or heat and cold.
Temporal
• May cause hallucinations that include old memories; presumably, neural circuits involved in
these memories are activated by the spreading excitation
• Seizures can also occur in Children.
14. CAUSES OF
SEIZURES
1. Scarring (common cause)-produced by an injury, a stroke,
a developmental abnormality, or the irritating effect of a
growing tumor.
2. Various drugs and infections that cause a high fever can
also produce seizures (Berkovic et al., 2006).
3. In addition, seizures are commonly seen in alcohol or
barbiturate addicts who suddenly stop taking the drug.
4. Genetic factors contribute to the incidence of seizure
disorders (Berkovic et al., 2006). Genes control the
production of ion chanels.
15. TREATMENT OF SEIZURES
1. Seizure disorders are treated with anticonvulsant drugs, many of which work by increasing the
effectiveness of inhibitory synapses. Most disorders respond well enough that the patient can
lead a normal life. Sometimes drugs provide little or no help.
2. Some times brain surgery is still required. The surgeon removes the region of the brain
affected
Mrs. R.’s treatment, described in the opening case of this chapter, was a different matter; in her
case the removal of a meningioma eliminated the source of the irritation and ended her
seizures. No healthy brain tissue was removed.
17. CEREBROVASCULAR ACCIDENTS (CVA)
Cerebrovascular accident (CVA) is the medical term for a stroke. A stroke is when
blood flow to a part of your brain is stopped.
Types of cerebrovascular accident
Ischemic stroke (caused by blockage)
An ischemic stroke is the most common and occurs when a blood clot blocks a
blood vessel and prevents blood and oxygen from getting to a part of the brain.
There are two ways that this can happen. One way is an embolic stroke, which
occurs when a clot forms somewhere else in your body and gets lodged in a
blood vessel in the brain. The other way is a thrombotic stroke, which is when
the clot forms in a blood vessel within the brain.
Hemorrhagic stroke
A hemorrhagic stroke occurs when a blood vessel ruptures, or hemorrhages, and
then prevents blood from getting to part of the brain. The hemorrhage may
occur in any blood vessel in the brain, or it may occur in the membrane
surrounding the brain
Both types of stroke deprive part of the brain of blood and oxygen, causing brain
cells to die.
18. SYMPTOMS
Difficulty walking dizziness
Loss of balance and
coordination
Both types of stroke
deprive part of the brain
of blood and oxygen,
causing brain cells to
die.
Difficulty in speaking or
understanding other
speakers
Numbness or paralysis
in the face, leg, and arm
(one side of the body)
19. Treatment for a cerebrovascular accident
Ischemic stroke treatment (Removing blockage)
A clot-dissolving drug or a blood thinner.
Aspirin to prevent a second stroke.
Injecting medicine into the brain or removing a blockage with surgery-imegency case
Hemorrhagic stroke treatment (controlling bleeding)
A drug that lowers the pressure in your brain caused by the bleeding.
Surgery to remove excess blood.
Surgery to repair the ruptured blood vessel
20. PREVENTIVE MEASURES
1. Maintain normal blood pressure.
2. Limit saturated fat and cholesterol intake.
3. Refrain from smoking, and drink alcohol in moderation.
4. Control diabetes.
5. Maintain a healthy weight.
6. Get regular exercise.
7. Eat a diet rich in vegetables and fruits.
22. TRAUMATIC BRAIN
INJURY
Almost a third of deaths caused by injury involve Traumatic brain injury (TBI)
Traumatic brain injury can be caused by a projectile or a fall against a sharp object that
fractures the skull, causing the brain to be wounded by the object or a piece of the broken skull.
Closed-head injuries do not involve penetration of the brain, but these injuries can also cause
severe injury or death.
Penetrating brain injuries (also called open-head injuries) obviously cause damage to the
portion of the brain that is damaged by the object or the bone.
23. EFFECTS OF TBI
MILD
A brain injury can be classified as mild if loss of consciousness and/or confusion and
disorientation is shorter than 30 minutes.
The individual has cognitive problems such as headache, difficulty thinking, memory problems,
attention deficits, mood swings and frustration.
SEVERE
Severe brain injury is associated with loss of consciousness for more than 30 minutes
and memory loss after the injury or penetrating skull injury longer than 24 hours.
The deficits range from impairment of higher level cognitive functions to comatose states.
Survivors may have limited function of arms or legs, abnormal speech or language, loss
of thinking ability or emotional problems. The range of injuries and degree of recovery is very
variable and varies on an individual basis.
24. MECHANISMS OF INJURY
These mechanisms are the highest causes of brain injury: Open head Injury,
Closed Head Injury, Deceleration Injuries, Chemical/Toxic, Hypoxia, Tumors,
Infections and Stroke.
1. Open Head Injury
Results from bullet wounds, etc.
Largely focal damage
Penetration of the skull
2. Closed Head Injury
Resulting from a slip and fall, motor vehicle crashes, etc.
Focal damage and diffuse damage to axons
Effects tend to be broad (diffuse)
No penetration to the skull
25. TREATMENT FOR TBI
There are many different kinds of treatments available for patients of Traumatic Brain Injury
(TBI).
Initial Treatment stabilizes the individual immediately following a traumatic brain injury.
Rehabilitative Care Center Treatment helps restore the patient to daily life.
Acute treatment of a Traumatic Brain Injury is aimed at minimizing secondary injury and life
support.
Surgical Treatment may be used to prevent secondary injury by helping to maintain blood flow
and oxygen to the brain and minimize swelling and pressure.
27. A common cause of mental retardation and underdevelopment is the
presence of toxins that impair fetal development.
These toxins can be released from the mother to the baby through viruses
from diseases such as Rubella,(German Disease), alcohol, smoking,any kind
of pollution that can happen in excess in the environment eg water
pollution, air pollution,land pollution.If a woman contracts a disease such
as Rubella, the toxic chemicals released by the virus interfere with the
chemical signals that control normal development of the brain.Most
women are immunized for Rubella to prevent them from contracting it
during pregnancy
Active and passive smoking have disastrous effects on the mother and
unborn children. Cigarette smoke contains nearly 4 000 chemicals such as
lead, cyanide and 60 other cancer causing compounds.When one smokes,
the toxins get mixed in the blood, the only source of nutrients and oxygen
for the baby. Nicotine and carbon monoxide work towards reducing the
supply of oxygen to the baby. Smoking also lowers the chances of
conceiving by at least 40%.
28. TOXIC CHEMICALS CONT…..
Serious complications result in stilbirth,premature delivery and
low birth weight. Nicotine narrows the blood vessels in one’s body,
including the one in the umbilical cord, forcing the baby to breathe
from a narrow passage.
In both babies and adults, the lack of proper development will lead
to underdeveloped growth of organs such as the heart and lungs.
This can lead to breathing problems and death.
The image shows how toxins caused by smoking can hinder
development:
29.
30. FETAL ALCOHOL SYNDROME
Ingestion of alcohol can also have adverse effects on development of human beings.
For pregnant mothers this can lead to fetal alcohol development which is characterised by
abnormal facial development and deficient brain development.
Tests which were done on pregnant mice which were ingested with alcohol showed similar
effects.
research suggests that alcohol interferes with the growth of neurons in the developing brain
and also interfering with a neural adhesion protein, a protein that helps to guide the growth of
neurons.
Prenatal exposure to alcohol also appears to have direct effects on neural plasticity, alters the
development neuronal cells and progenitor cells.
33. INHERITED METABOLLIC DISORDERS
There are at least a hundred or thousands different inherited
metabolic disorders that can affect the development of the brain. The
most common one is Phenylket Uria.
A Few other common inherited metabolic disorders are going to be
discussed.
The term metabolism refers to all biochemical processes and
pathways in the body. Enzymes play a role in many of these processes
and changes in their function, as a result of genetic mutation can lead to
problems in these pathways, thus the term inherited.
35. This disease is caused by an inherited lack of an
enzyme that converts phenylalanine (an amino acid)
into tyrosine, (another amino acid.)
Basically the liver cells are unable to effectively break
down the amino acid called phenylalanine, which is
present in most foods. When left untreated, this builds
up in the bloodstream becoming toxic and over time
rises to dangerous levels, damaging the brain causing
mental retardation and other irreversible affects.
Each person with PKU can tolerate varying levels of
protein a day which needs to be spread evenly across
the day to avoid spiking of phenylalanine levels. To
give you an example of how extreme the PKU disorder
is, one egg is equal to approximately 6 grams of
protein. The average person with classic PKU can
tolerate 4 to 10 grams a Day. An egg would be too
much protein, and would cause blood levels to be too
high and start to cause damage.
Phenylketonur
ia
(PKU)
38.
Treatment involves, a
strictly controlled
phenylalanine free diet
up to the age of about
14 years
old.Phenylalanine is
itself an
essential amino acid .
Blood levels need to be closely monitored through a home
blood test which needs to be sent to the screening laboratory for
results.
Although PKU is a very rare disorder, one in fifty individuals in
the normal population are carriers of the gene that causes PKU. A
person with PKU has inherited the defective gene from both
parents and only occurs when both parents carry this gene.
Excessive amounts of phenylalanine in the blood interferes with
the myeliinization of neurons in the Central Nervous System.
Much of the myelinization of the cerebral hemispheres take place
after birth.
So when an infant born with PKU receives foods containing
phenylalanine , the amino acid accumulates and the brain fails to
develop normally.
42. Galactose forms half of the sugar lactose, which is found in
milk. The other half of lactose is made of glucose.
There are three forms of this disease. These include type I
or classic galactosemia, which is the most common and
severe form of the disease, type II which is also referred to as
galactokinase deficiency and type III which is also called
galactose epimerase deficiency.
Affected babies may develop symptoms within the first few
days of life if they consume any lactose. These symptoms
include the following: Convulsions Lethargy Yellowing of the
skin and whites of the eyes (jaundice) Irritability Vomiting
Refusal to eat Poor weight gain Bleeding Galactosemia type II
causes fewer problems than type I, with infants developing
cataracts, but few long-term problems.
The symptoms of galactosemia type III vary in severity and
can include growth and developmental delay, liver disease,
cataracts, kidney problems and intellectual disability.
Galactosemia is a disease that cannot be cured.
43. Spleen damage Cataracts Reduced bone density
Premature ovarian failure in females Babies with
galactosemia cannot be fed any breast milk or infant
formulas containing lactose.
The only way to manage galactosemia is to eliminate
lactose and galactose from the diet completely.
However, even when galactosemia is detected and
treated early, some individuals still go on to
experience long-term complications. Some of these
complications include: Brain damage Speech
difficulties Learning disabilities Kidney damage Liver
damage.
Galectosemia is also found in some non-milk
products such as legumes, organ meats and as an
additive in some food products. Instead, infants can
be fed using soy-based formulas, meat-based formulas
or another lactose-free formula.
44. This disorder occurs when the liver fails to properly dispose of
ammonia, a waste product of protein digestion. Six enzymes are
involved in the urea cycle, a process that converts the toxic
substance ammonia into urea, which is excreted in the urine.
The six enzymes in the urea cycle are ornithine
transcarbamylase (OTC), argininosuccinic acid synthetase (ASD),
arginase (ARG), arginosuccinase acid lyase (ALD), carbamyl
phosphate synthetase (CPS), and N-acetylglutamate synthetase
(NAGS).
These enzymes are found in the liver, where they process
nitrogen-containing waste products (such as ammonia) into
urea. Deficiencies in any of these enzymes, also known as
inborn errors of urea synthesis, can lead to urea cycle disorders.
If an enzyme or transporter in the urea cycle is deficient,
ammonia may build up in the blood and reach toxic levels. An
elevated ammonia level (hyperammonemia) disrupts normal
brain and central nervous system function. Some of the physical
Urea Cycle
Disorder
45. symptoms may include lack of appetite, irritability,
heavy or rapid breathing, low energy, vomiting,
disorientation, and combativeness. If left untreated, high
ammonia levels may lead to coma, swelling of the brain,
brain damage, and death
In a urea cycle disorder, ammonia levels may be
increased after a meal high in protein, viral illness,
childbirth, and certain prescription medications.
Urea Cycle
Disorder
53. Type 1 diabetes (T1D): The body stops producing insulin or
produces too little insulin to regulate blood glucose level. Type 1
diabetes is typically diagnosed during childhood or adolescence.
Insulin deficiency can occur at any age due to destruction of the
pancreas by alcohol, disease, or removal by surgery. Type 1 diabetes
also results from progressive failure of the pancreatic beta cells, the
only cell type that produces significant amounts of insulin. People
with type 1 diabetes require daily insulin treatment to sustain life.
Type 2 diabetes (T2D): Although the pancreas still secretes insulin,
the body of someone with type 2 diabetes is partially or completely
incapable of responding to insulin. This is often referred to as insulin
resistance. The pancreas tries to overcome this resistance by
secreting more and more insulin. People with insulin resistance
develop type 2 diabetes when they fail to secrete enough insulin to
cope with their body's demands. Type 2 diabetes is typically
diagnosed during
DIABETES
54. adulthood, usually after age 45 years. It was once called adult-onset
diabetes mellitus, or non-insulin-dependent diabetes mellitus. These
names are no longer used because type 2 diabetes does occur in young
people, and some people with type 2 diabetes require insulin therapy.
Type 2 diabetes is usually controlled with diet, weight loss, exercise,
and/or oral medications. However, more than half of all people with
type 2 diabetes require insulin to control their blood sugar levels at
some point during the course of their illness.
Gestational diabetes (GDM) is a form of diabetes that occurs during
the second half of pregnancy. Although gestational diabetes typically
resolves after delivery of a baby, a woman who develops gestational
diabetes is more likely than other women to develop type 2 diabetes
later in life. Women with gestational diabetes are more likely to have
large babies.
Metabolic syndrome (also referred to as syndrome X) is a set of
abnormalities in which insulin-resistant diabetes (type 2 diabetes) is
almost always present along with hypertension (high blood pressure),
high fat levels in the blood (increased serum lipids)
DIABETES
55. central obesity, and abnormalities in blood
clotting and inflammatory responses. A high rate of
cardiovascular disease is associated with metabolic
syndrome.
Prediabetes is a common condition related to
diabetes. In people with prediabetes, the blood
sugar level is higher than normal but not yet high
enough to be considered diagnostic of diabetes.
Prediabetes increases a person's risk of developing
type 2 diabetes, heart disease, or stroke.
Prediabetes can typically be reversed (without
insulin or medication) by lifestyle changes, such as
losing a modest amount of weight and increasing
physical activity levels. Weight loss can prevent, or
at least delay, the onset of type 2 diabetes.
DIABETES
56. OBESITY
Genetic factors
Heritability of Obesity is about 66%. Genetic factors may
affect the many signaling molecules and receptors used by
parts of the hypothalamus and GI tract to regulate food
intake . Genetic factors can be inherited or result from
conditions in utero (called genetic imprinting). Rarely,
obesity results from abnormal levels of peptides that
regulate food intake (eg, leptin) or abormalities in their
receptors (eg, melanocortin-4 receptor)
Environmental factors
Weight is gained when caloric intake exceeds energy needs.
Important determinants of energy intake include portion
sizes and the energy density of the food. High-calorie foods
(eg, processed foods), diets high in refined carbohydrates,
and consumption of soft drinks, fruit juices, and alcohol
promote weight gain. Diets high in fresh fruit and
vegetables, fiber, and complex carbohydrates, with water as
the main fluid consumed, minimize weight gain. A
sedentary lifestyle promotes weight gain.
66. Pathology of
Cell Death:
Necrosis
an injured cell form which results
in the premature death of cells in
living tissue by autolysis.
It’s caused by external factors.
Apoptosis
a process of programmed cell
death
lead to characteristic cell changes
and death.
79. [ Symptoms]
Huntington’s
Disease
Atrophy
Usually age 35 – 45 (+ or – 17 years)
Men and women equally
Younger people with Huntington's
disease often have more severe
case, and symptoms may progress
more quickly